Adoption Citizenship

Thanks to the Child Citizenship Act,internationally adopted children under 18 years old became citizenships of the United States, as of February 27, 2001.

Children receiving an IR-3 during their adoption (ie, single adoption or both parents traveled to Vietnam) should receive their
Certificates of Citizenship within 45 days of their arrival.

A child who enters the United States on an IR4 visa (to be adopted in the United States) will become a American citizenship when their adoption is finalized in the United States. At that time, you can apply for a passport for them (as described in the above link) or they can receive the Certificate of Citizenship by filing the N-600 form, at a cost of $420.